If I peel, cut, prep kohlrabi in advance of serving, how long will it stay fresh?
Sometimes I keep large slices of it in a covered container in the refrigerator for 3 or 4 days. But I just eat it fresh in slices along with carrots and celery. If it were more finely chopped or grated I don't know that I would keep it more than a day or two and I would refrigerate it.
Agree with first comment. Generally, I prefer the color & texture of fresh or recently cut kohlrabi.
If you need to prep a large volume & must cut in advance, you'll get better results if you freeze the cut veg (for later use in a cooked dish), or store in water in fridge for a day (drain for use as raw veg).